Our Flow Cytometry Size Calibration Kit has nonfluorescent particle-size calibration standards that provide a simple, accurate way to determine cell sizes by flow cytometry. The kit contains six suspensions of highly uniform polystyrene microspheres with the following diameters: 1.0 µm, 2.0 µm, 4.0 µm, 6.0 µm, 10.0 µm and 15.0 µm. All of the microsphere suspensions are provided in convenient dropper vials.